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  #11  
Old 04-13-2013, 11:37 PM
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JimN JimN is offline
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Originally Posted by thatsmrmastercraft View Post
Not that I would recommend using low octane fuel, but doesn't the LT-1 have a knock sensor to retard the timing when experiencing detonation or pre-ignition to prevent damage? Of course the lack of performance with retarded timing wouldn't be any fun either. This coming from a Ford guy with a 1977 boat.
All injected engines have a knock sensor but the LT-1 is higher compression, so it needs higher octane to prevent detonation. Lower octane fuel burns faster, so the combustion won't occur when it's supposed to, nor for the same duration.
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  #12  
Old 04-13-2013, 11:40 PM
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Originally Posted by supreme112279 View Post
The lt1 being a high performance engine, it like higher octain gas. IT would problally run just fine on 87 but 89/90 would be better and 93 would be best. ethanol is ok if you use your MC often but I hate it. I personally run 93 non ethanol. on the knock sensor, Im not convinced it really works. My camero doesent run any different with it unpluged.
Re-connect the knock sensor, connect a timing light and start the engine, rev it up and hit a motor mount with a hammer if you want to see if it works. If nothing happens, check the knock sensor to see if it's bad. If you use the car in a hot, dry region, you can do a lot of damage to your engine in hte event that detonation (knock) occurs.
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  #13  
Old 04-13-2013, 11:42 PM
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Originally Posted by j.mccreight@hotmail.com View Post
The ecm is only able to retard the timing a couple of degrees, it will throw a mil beyond 5 degrees, continually using low octane with hard driving it will ping. Also fuel loses octane over time so add that to the equation.

Of course you already knew this
The ECM backs the timing off in 5 degree increments, until base timing is reached. When the engine is running at high RPM, it can need close to 35 degrees of spark advance in addition to the 10 degrees BTDC at idle for base timing. Big difference in performance between 45 degrees and 10 when it's running at WOT.
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  #14  
Old 04-14-2013, 09:18 AM
supreme112279 supreme112279 is offline
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Quote:
Originally Posted by JimN View Post
Re-connect the knock sensor, connect a timing light and start the engine, rev it up and hit a motor mount with a hammer if you want to see if it works. If nothing happens, check the knock sensor to see if it's bad. If you use the car in a hot, dry region, you can do a lot of damage to your engine in hte event that detonation (knock) occurs.
Thats a good idea. I always leave it hooked up. That was a test a friend and I were messing around.
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  #15  
Old 04-14-2013, 09:30 AM
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Originally Posted by supreme112279 View Post
Thats a good idea. I always leave it hooked up. That was a test a friend and I were messing around.
You won't see it do anything unless you or the engine cause the sounds the sensor is sensitive to- it's basically a narrow-band microphone and at idle, it's almost completely unlikely to pick up anything.
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